The present invention relates to etching a layer of non volatile materials through a mask during the production of a semiconductor device. More specifically, the present invention relates to etching a metal containing layer.
During semiconductor wafer processing, features may be etched through a metal containing layer. In the formation of magnetoresistive random-access memory (MRAM) or resistive random-access memory (RRAM) devices, a plurality of thin metal layers or films may be sequentially etched.
The etching of such MRAM layers is very challenging due to extremely low vapor pressure of the etch by products formed. Some MRAM etch processes are sputter dominated processes, which cause the loss of control of profile angle and sidewall polymer buildup. These results prevent scaling down feature size and reduce device reliability.